Frogs muscle-in on wasting process

Scientific studies of a unique Australian frog could lead to the development of new ways to improve livestock production levels and boost the prospects of maintaining human muscle strength into old age.

According to CSIRO Livestock Industries' post-doctoral fellow, Dr Nick Hudson, the green-striped burrowing frog (Cyclorana alboguttata) can remain buried in mud for months in an inactive state known as 'aestivation', without any effect on its muscles.

Dr Hudson is part of a collaborative team of researchers, from CLI and the University of Queensland who hypothesise that the mechanisms underlying the frog's ability to maintain muscle mass despite starvation, could provide natural and novel ways of optimising muscle production from cattle, sheep, pigs and goats.

'If we can understand how the frog does this, we may be able to target specific genes, or develop new treatments, to enhance muscle mass during the growth of livestock species, or to limit muscle loss during times of nutritional deprivation, such as drought.'

Similarly, muscle wasting experienced by astronauts, bed-ridden patients and the elderly, could be addressed.

'A person forced into similar inactivity, would lose in excess of 90 per cent of their muscle strength. This is both a health burden for global populations and a barrier to space exploration,' Dr Hudson says.

Dr Hudson is using microarray technology to compare gene expression in the muscles and other tissues of the frog and cattle. Genes that are active during aestivation will be used to identify related genes in cattle, for further study. Information from the bovine genome sequencing project will assist this process.

The research also aims to provide further insight into the phenomenon of aestivation in the burrowing frog. Current hypotheses suggest that it produces high levels of antioxidants within the muscle, which inhibit muscle protein breakdown normally associated with disuse.

'In aestivation, the frog can lower its metabolic rate by about 90 per cent and - unlike animals undergoing hibernation, it does this while it's still warm,' Dr Hudson says.

'There are theories on how this happens, but hopefully our three-year research project will clarify these and define the genes and regulatory networks involved.'